I could be wrong, but I don't believe that Eaton makes an E-locker for the 8.25 axle?
If you are set on using the E-lockers, you might want to think about a different rear axle upgrade.

I suppose what's important then is the difference in ability of 35's and 38's.

Thoughts?

Money's not really an issue here I've got a free place to stay and travel is free, I built a computer now I'm ready to dump money into the jeep, just wanna make sure it will be justified.

Honestly just stick with 35s unless you're trying to build a crawler

No Eaton ELockers for the 8.25"
I'd suggest a Detroit out back, ELocker up front.
another option is to swap in a Ford 8.8 or D44 out back, Elockers can be had for both.

the ability to break more drivetrain parts w/ less effort comes to mind. i once went from 35's to 37's on a well built cj w/ a d44 front & 9" rear, it wasnt worth the 1" of ground clearance. kept breaking front shafts & u joints, until i went to alloy shafts & alloy joints. then i still stayed easy on the gas pedal, just to be safe. i didnt really notice the jeep had anymore trail ability w/ the bigger tires.

Why do you feel that you need 38's? I understand the desire to go bigger, but you're skipping the steps in-between. Get some 35's, HP-30, and a 8.25 for cheap, wheel the **** out of it, then if you want more, step up to bigger meats.

A simplified list for going big:
D60 front
14 bolt/Sterling rear
"Frame" reinforcement
Suspension (3/4-link would be optimal)
Deep gears (5.13+)
Lockers
Bigger t-case (twin sticks are nice. Get a doubler if you're feeling really frisky)
Tires (expensive in large sizes)
Driveshafts
Cage (you WILL need one)
$$$$

Basically go on Pirate, and check out the rigs in the "bad *** cherokees" thread.

Great advice and info...